Transmission synchromesh mechanism



June 5, 1951 w. 1. DUNN 2,555,961

TRANSMISSION SYNCHROMESH MECHANISM Filed Nov. 727, 1946 4 Sheets-Shet 1BMM/w@ HTTORNZ'VS 'June` 5, 1951 w- T, DUNN 12,555,961

TRANSMISSION SYNCHROMESH MECHANISM Filed Nov. 27, 1946 4 ShaetS-Sheet 2INVENTOR.

Zz'am vwrl.

HTTORNEYS w. r. DUNN musurssou sYNcmzouEsH cmmrsu June 5, 1951 4Sheets-Sheet 5 Filed- Nov.v 27, 1946 INVENTOR. i MIL-am vnm v BY 1 June5, 1951 w 1', DUNN 2,555,961

TRANSMISSION sYNcHRoMEsH macmmsmlv Filed Nov. 27, 194e '4 sheets-sheet 44 IN VEN TOR.

BY@ i I wrom/Em.

Patented June 5, 1951 TRANSMISSION SYNCHROMESH MECHANISM William T.Dunn, Detroit, Mich., assgnor to Chrysler Corporation, Highland Park,Mich., a corporation of Delaware- Application November 27, 194s, serialNo. 712,541

22 Claims.

This invention relates to an improved power transmitting mechanism ofthe type adaptedlfor use in a motor vehicle drive system in whichposiltive clutch means is employed to drivingly connect torquetransmitting structures.

, An object of the invention is to provide simple and efficient meansoperable to eliminate clashing of the parts to be clutched as anincident to difference in speed of rotation thereof.

The invention has particular application to a YVehicle drive systemincluding a plurality of posij tive clutches and a friction clutchassociated with each positive clutch to facilitate operation of thelatter.

Another object of the invention is to provision in a synchromeshmechanism of a frictionclutch of the blocker type which operates in aminimum of time to control the rotative speeds of the parts to beclutched and which is timely energized to releasably block asynchronouspositive clutching;

and more particularly to provide an improved arrangement by which thecomponents of a fric- Ytion clutch for a synchromesh mechanism arerelatively positioned for energizing the blocker of such clutch.

i Transmission mechanisms of the type used in torquetransmitting'structures and a third structureA adapted to beselectively, positively clutched therewith to provide relativelydifferent speed ratio drives, and an additional object of the inventionis the provision of friction clutches of 'the blocker type respectivelycontrolling such positive clutching and wherein a component of one suchfriction clutch cooperates with a component of another clutch toposition the components of each friction clutch for continuousfricsembly and subsequent wear, and in this respect the inventionprovides for the development of an energizing pressure at one frictionclutch which is transferred to the other thereof through engagingcomponents of these clutches; or in the alternative the inventioncontemplates the development of an energizing pressure at each suchclutch, with one of these clutches reaching against the other under theinfluence of this pressure.

A further object is the provision in a synchromotor vehicle drivesinclude relatively rotatable mesh transmission of a friction clutch orclutches having a relatively large diameter and in which the zone offriction clutching is substantially `radially outwardly of the zone ofpositivel clutching, and to provide an arrangement which will facilitaterelative movement of the various clutch 'components to effect operationof each type of clutch.

` Other objects and advantages of the invention will be more apparentfrom the following description taken in connection with the accompanyingdrawings in which:

Fig. l isa fragmentary elevational view of a synchromesh transmissionembodying the invention;

l Fig. 2 is an enlarged fragmentary sectional elevational view taken asindicated by the line 2-2 of Fig. l;

Fig. `3 is a transverse section taken on line 3-3 of Fig. 2; i

Fig. 4 is an enlarged fragmentary top plan view illustrating theblocking position of components of the synchromesh mechanism;

Fig. 5 is a view similar to Fig. 2 but illustrating a modified form ofthe invention;

Fig. 6 is a transverse section taken on line 6 6 of Fig. `5;

Fig. 7 is a fragmentary exploded view in perspective showing certain ofthe components of the clutches prior to nal assembly;

Fig. 8 is a view corresponding to Fig. 2 but illustrating a furthermodification of the: inven- 1 tion;

Fig. 9 is a transverse sectional view taken on line 9-9 of Fig. 8;

Fig. 10 is an enlarged fragmentary top plan view illustrating theblocking position of components of the Fig. 9 synchromesh mechanism;

Fig. 11 is a view similar to Fig. 2, but illustrating a furthermodification of the blocker energiz- .ing for each friction clutch;

Fig. `12 is a View similar to Fig. 5, but illustratf ing a furthermodification of the blocker energizing for each friction clutch;

Fig. l3'is a View similar to Fig. 8, but illustrating a furthermodification of the blocker energizing for each friction clutch;

Fig. 14 is a fragmentary perspective view ofte.

blocker energizing spring shown in Figs. 11, 12,

and 13.

` The invention is illustrated and described in l conjunction with asynchromesh mechanism for r a Imotor vehicle transmission presently usedalfthough it will be` understood that the improvements may be applied toother transmission arbe of the well known form and arrangement cur yrently used in motor vehicles.

The shaft I3 carries a main driving gear |1 which is in constant meshwith a gear IB of a countershaft gear cluster mounted for rotation on acountershaft I9. The gear cluster includes a second speed gear 26 inconstant mesh with a second speed gear 2| rotatably mounted on thetransmission driven shaft 22 adapted to be connected to the groundwheels of the vehicle in the well known manner. Such transmissioncontemplates provision of the usual reverse drive and also a low speeddrive, but the same are omitted here for the sake of brevity inasmuch asthe invention is applied herein to the direct and second vspeed drives.rEhe gear 2| is retained axially sta- Y tionary between a shoulder 23 onshaft 22 and a hub 24 splined to the latter, abutting gear2l, andretained by a snap ring 25. external splines 24. The shaft I5 has a setof `clutch teeth 23 to which is splined a friction 'clutch part 21having a frusto-'conical peripheral surface, and the gear 2| has a setof clutch teeth y28 to which Vis splined a friction clutch part 294having a frusto-'conical peripheral surface.

Referring particularly to Figs. 1 to 4, inclusive, -a clutch sleeve 30having internal teeth 3| drivingly engaged with the hub splines 24 ispositioned between the sets of teeth 25, 28 and is lvadapted to beaxially shifted to selectively clutch therewith, to provide a directdrive between shafts |6, v22 when clutched with teeth 23,- and a secondilspeed drive therebetween when clutched with -teeth 28. Each suchshiitis made under control of synchronizing meansfor insuring uniformro- 4 larged portion of each finger entering the regis tering recess 33.

The element 33 is similar to element 32 and has an annular portion 39provided with a frustoconical internal surface engageable with 4theexternal surface of part 29, and a plurality of circumferentially spacedgenerally axially extending fingers 613, preferably integral withportion 39.

AYEach finger 43 extends into a recess 36 in sleeve 33 to rotatablyconnect element 33 with sleeve 30 and each finger has a width less thanthe circumferential dimension of the recess to permit limited relative'rotation between element 33 and sleeve 39'. As shownV in Fig. 4, eachfinger 4o is reduced in width to provide opposed cam shoulders 4|respectively engageable with cam shoulders 42 at that end of recess 36adjacent part 29. The element 33 operates to control shift of sleeve 30to clutch with teeth 2B in the same general man- 'ner as the aforesaidoperation of the element 32.

The ends of each registering pair of fingers 35,

Y 4e abut to position the elements 32 and 33 for The hub has tation ofthe teeth to be clutched and means for preventing a complete clutchingshift of the sleeve until a synchronized relationship of the clutchingteeth is established. This control means includes "synchronizingfriction clutch elements 32 and 33 respectively operably associated withthe parts 21 and 29. 'i The friction element 32 includes an annularIportion 313 having a frusto-conical surface en- Agagealole with theexternal surface of part 21 and ,a plurality of circumferentially spacedgenerally f axially extending fingers, parts as projections 35,preferably integral with portion 34, respectively extending intorecesses in the outer periphery of the sleeve 33 to rotatably connectelement 32 with the latter. i cumferential dimension greater than thewidth of the finger -to accommodate limited relative rotation betweenelement 32 and sleeve 30. As shown in Fig. 4, Yeach finger 35 is reducedin width to provide opposed cam shoulders 31 respectively engageablewith cam shoulders 38 at the entrance u. o the receiving recess 36 forblocking shift of sleeve 30 to clutch withv teeth 26, a shoulder 31being adapted when so engaged with a shoulder A38 to receive axialthrust from sleeve 3|) to force ij the element 32 into synchronizingfrictional driv- -ing engagement with part 21 during shift of 4sleeve3i) to clutch with teeth 23. When such engagement is establishedrelative rotation of ele@` "ment 32 vand sleeve 33 will occur permittingthe sleeve to complete its clutching shift, the enl:for wear of thecomponents. `developed at the friction clutch for the gear 2| relativelylight frictional engagement with the respective parts 21 and 29, thisengagement being of a degree sufncient tocause each element to rotaterelative to sleeve 3U to dispose the fingers 35, 4G at one extremecircumferentially of the recess 36 and thereby dispose the shoulders 31,4| in blocking position as shown in Fig. 4. Thus, when the speed ofrotation of each set of teeth 23, 23 varies with respect to the rotativespeed of clutch 33, the shoulders 31, 4| are disposed in blockingVrelation relative to the sleeve 33, and each element is so positionedindependently of the other.V Tendency of the elements 32, 33v to move ina direction to separate from the cooperating friction part is opposedand'lirnited by engagement of the fingers. Y

While the initial abutting engagement of 1ingers 35, #t may beestablished on assemblyV and relied upon to produce the necessarylightv'frctional engagement to energize the blockers as aforesaid,nevertheless it may be expedient for manufacture and assembly to providefor greater tolerances than wouldexist in the construction so fardescribed and I have, therefore, provided la plurality of coil springs43 each received in a bore 44 of gear 2| and exerting an axial thrustagainst friction part 29. The action of such springs will take upclearances resulting from variations in manufacture and will compensateThe axial thrust will be transmitted to the otherA friction clutch forthe gear |1 through the abutting fingers 35, 40.

If desired the internal surface of each element 32, 33 may be threadedand such element may be made from sheet metal.

The clutch sleeve 33 has secured thereto by pins 45 a shift collar 43channelled to receive the shifting fork of the well known shiftingmechanism. Y

Referring to Figs. 5, 6, and 7, a clutch sleeve 41 has internal teeth 48splined t'o hub teeth 24' and is adapted for opposite axial shift toselectively clutch teeth 48 with teeth 23V to provide a direct drivebetween shafts I6, 22 or to clutch with teeth 28 to provide a secondspeeddrive between such shafts. Each such shift is made under control ofsynchronizing` means for insuring uniform rotationof the teeth to beclutched ship'of the clutching teeth is established. This control meansincludes synchronizing friction 5 clutch elements 49 and 5U,respectively operably associated with the parts 21, 29.

The element 49 has an annular internal frustoconical surface engageablewith the exterior surface of part 21, a radially inwardly extendingiiange 5|, and a plurality of circumferentially spaced `axiallyextending fingers 52 respectively extending into openings 53 in clutchsleeve 41 to provide a lost motion driving connection between element 49and sleeve 41, each opening and finger having circumferential clearancesufcient'to permit limited rotation between element 49 and sleeve 41. Aportion of the flange 5| intermediate adjacent fingers 52 is removed asindicated at 54, to provide space to' accommodate moveastucci ment ofthe sleeve 41 to clutch with teeth 2E.

shift of sleeve 41 to clutch with teeth 25, a

shoulder 55 being adapted when so engaged with a shoulder 55 to receiveaxial thrust from sleeve 41 to force the element 49 into synchronizingfrictional engagement with part 21 during shift of sleeve l1 to clutchwith teeth 26. When such engagement is established relative rotation ofelement 49 and sleeve 41 Will occur permitting the sleeve to completeits clutching shift, the enlarged portion of each nger entering theregistering opening 53.

The element 50 is similar to element 49 and has an annular internalfrusto-conical surface engageable with the external surface of part 29,a radially inwardly extending flange 51, and a plurality ofcircumferentially spaced fingers 58 respectively projecting intoopenings 53. portion of the fiange 51 intermediate adjacent fingers 58is removed as indicated at 59 for providing space to accommodatemovement of sleeve 41 to clutch with teeth 28. Each finger has oppositecam shoulders one of which is shown at 65 in Fig. '7, respectivelyengageable with shoulders 6| at the adjacent entrance of opening 53 forblocking shift of sleeve 41 'to clutch with teeth 28 and to receiveaxial thrust for forcing element l] into synchronizing frictionaldriving engagement with part 29. When such engagement is establishedrelative rotation between sleeve 41 and element 50 will occur, suchbeing permitted by the lost motion rotary connection provided by eachfinger 58 in the opening 53 and the circumferential clearance existingthereat. At final clutching the enlarged portion of each finger 58 willbe in the registering recess 53 of the sleeve and the latter will passthrough the openings in flange 51 provided by cutting the same away asindicated at 59.

The ends of each registering pair of ngers 52, 58 abut to position theelements 49, 5G for relatively light frictional engagement with theassociated parts 21, 29, this engagement being of a degree sufficient tocause each element `to rotate relative to sleeve 41 to dispose thefingers 52, 5B at one extreme circumferentially of the opening 53 andthereby dispose one of the shoulders 55, 60 in blocking position, thatis, in registration with a sleeve shoulder 55, 6l. Thus, when either setof teeth 2E, 28 is rotating at a speed different from that of the sleeve41 either element is free to establish its blocking positionindependently of the other. f

Here, as in the foregoing arrangement, engagement` of the registeringfingers 52, 58 may be relied upon to position the elements 55, 50 forrelatively light frictional engagement with the cooperating parts,althugh it may be expedient to use springs 43 as pointed out above.

\ The clutch sleeve 41 is provided with a peripheral channel formingpart S2 adapted to receive a shifting fork of any well known shiftingmechanism. Referring to Figs. 8, 9. and 10, a sleeve 63 has internalteeth 64 splined to hub teeth 24 and is adapted for opposite axial shiftto selectively clutch the teeth thereof with teeth 26 to provide adirect drive between shafts l5, 22, or

to clutch with teeth 28 to provide the second speed drive between suchshafts. Each such shift is made under control of synchronizing means toinsure uniform rotation of the teeth to be clutched and means preventinga complete clutching shift until the synchronized relationship isestablished. This control means includes synchronizing friction clutchelements 65.and 66, respectively operably associated with parts 21, 29.f The element 65 includes an annular portion 61 having'a frusto-conicalinternal frictionsurface engageable with the external surface of part 21and a plurality of circumferentially spaced axially projecting fingers58 extending into axial openings 69 in sleeve 63. Each finger is reducedin thickness to provide a radially outwardly extending and axiallyfacing abutment and is reduced in width providing opposite cam shoulders'il respectively engageable with cam shoulders 12 at `the adjacententrance of opening 68 for blocking shift of sleeve 63 to clutch withteeth and to receive axial thrust for forcing element into synchronizingfrictional driving engagement with part 21. Each opening E9 iscircumferentially larger than the width of the finger portion normallyreceived therein to accommodate limited rotation between sleeve 63 andelement 65, and when the aforesaid engagement is established relativemovement will release the blocking shoulders 1l, 12 to permit completionof the clutching shift of the sleeve.

The element 66 is similar to element P55 and has an annular portion 13provided with an internal frusto-conical friction surface engageablewith the external surface of part 29, and a plurality ofcircumferentially spaced axially projecting ngers 14 respectivelyextending into openings G9 of the sleeve E3. Each finger 14 is reducedin thickness to provide a radially inwardly extending axially facingabutment 15 and isV reduced in width providing opposite cam shoulders 15respectively with cam shoulders 11 at the adjacent entrance of opening69 for blocking shift of sleeve 53 to clutch with teeth 28 and toreceive axial thrust for forcing element 65 into synchronizingfrictional driving engagement with part 29. Each opening 65 iscircumferentially larger than its finger 68 to permit limited relativerotation between sleeves 53 and element 66 and when the aforesaidengagement is established relative movement will release the blockingshoulders 15, 1l to permit completion of the clutching shift.

Each pair of registering fingers 58, 14 overlap in the receiving recess69 and cooperate one with the other to position the element G5, 66 inrelatively light frictional engagement with the respective associatedparts 21, 29. For this pur; pose the free end of each finger 68 engagesthe shoulder 15 of its registering finger 14 and the free end of each ofthe latter fingers engages the abutment 10 of the registering finger 68.although for Apurposes of manufacture and assembly it may be expedientthat only one such free end and? abutment of a registering pair offingers engage andthis engagement will be s'uicient to position theelements for relatively A light fifictiohal engagement with itscooperating part.

It will be. understood that the latter engagement is of aV degre'esufn'cient to' cause an.- element 6.5, SE' to rotatewith its cooperatingpartV 2.1,-29 Ato one. extreme relative. to recesses .69, when` the'speedv of rotationof sleeve 63 differs from that of' either teeth 26 or28', and. thereby dispose a caifnA shoulder'V il in'blocking relation.`to a' shoulder" 12 and acam shoulder 1B in blocking relationto ashoulder 11. The sleeve 63'fis' provided with a channel` 18- to reeeiveayoke of the well-'known mechanism for shifting the sleeve axially asaforesaid. Referring.. to Fig. 11, the construction and operationof themechanism is substantiallyv'.simi,-l lair to that of Fig. 2, except thateach friction part 21,29 is biased in a direction Aaxiallylto maintaincontinuous light frictional engagement of each friction clutch toenergize. the `blocking means asV aforesaid. For this purposetwo springs19` are employed, one between thegear 2|' and part 29;, and the otherbetween the gear kl'i and part 21, and as typied in Fig. 14 such'spring19 is shown as an undulat'ed Washer-likey spring although other forms ofspring are contemplated in the broad aspect of the invention. Fig. l2 isa. showingsimilar to Fig. ,5, but in y cliiding a spring19 specicallybiasing the part 21V in a` direction to maintain relatively lightfrictional engagement with the element 49 to energize the blocking meansof the latter. g

.In Fig. 13 the construction and operation of the mechanism is similar.to that of Fig. 8, but springs 19`are employed tobias the parts 21, 29in' a direction to maintain relatively light frictional' engagement ofthe parts of each frictionV clutch.

I claim:

1. In a synchromesh transmission, a plurality of torque transmittingstructureseach,including a set of clutch teeth and a friction clutchpart, a

clutch member between said. sets of. teeth and axially shiftable from aneutral position` to selecd tively clutch therewith, relatively axiallymovable friction' clutch' elements respectively associated with said.partseach including a friction surface anda plurality of fingersinterengaged with said clutch member to form a rotary lost motiondriving connection therewith and having blocker means adapted' formovement betweena position to allow a selected clutching shift of saidmember Y and a position to block the same by engagement of such frictionsurface with itsv associated part, the ngers of each element abuttingthe' other element when the clutch member is in its neutral position toposition such other elem-ent fori continuous engagement of its frictionsurface' with the associated part, at least one of'said friction clutchparts being disposed for axial movement relative to its said structure,and spring means acting on said one friction clutch part constantly.biasing the same in an axial direction intov continuous frictionalengagement with the friction .surface of the associated'element.

.2. Ina power transmitting mechanism including axially spaced coaxialVVtorque transmitting members each having a set of clutch teeth and afriction clutchr part rotatable therewith, a clutch member coaxial withsaid members and 'selec'- tively shiftableA to clutch with the clutchteeth thereof, friction clutch elements rotatable with ,said thirdclutch member respectively cooperating with said partslto form frictionclutcheasad elm'entsfbeing constructed and arranged for relative axialopposite movements. in response to selective clutching shift of saidclutch member to relatively'rnovesaid elements; axially and thrustonefjthereof into synchronizing engagement. with its cooperatingfriction part `and said elementsbeing movable one toward the other torelease said synchronizing engagement, Vthe zone of frictioriallengagement of. each friction `vclutch being disposed radially outwardlybeyond 'said .sets of clutch teeth .and said. clutch member having. aplurality of circumferentiallyl spaced recesses radially intermediatesaid` VZones andv saidsets of clutch teeth, each ofsaid movable elementshaving' an annular part carrying the friction vsurface thereof' and aplurality of circumferentially spaced parts respectively extending intosaid re.- cesses, those parts in each recess being arranged inlaxialoverlapping4 relationship and the, overlaping .part ocne of each of saidelementsV being engageable with the. other Ycf, said elements tolimitmovement of said elements one toward the other.

3( In a' power transmitting mechanism including axiallyspacedY coaxialtorque transmitting members each having a set of clutch teeth and a..:friction clutch part` rotatable therewith, a clutch member coaxial withsaid members and selectively shiftable to clutch with the, clutch teeththereof, friction clutch elements rotatable with said third clutch.member respectively cooperating with said parts to formy frictionclutches, said elementsy being constructed and arranged for relativeaxial opposite movement inresponse to selective clutching shift of saidclutch member -to .relatively move said elements axially and thrust' one,thereof into synchronizing engagement with its cooperating, friction.part and said elementsA being movable one toward the otherto-releasesaid synchronizingengagement, the zone of frictional engagementof each friction` clutch being. disposedfradially outwardly beyond saidsets of clutch teeth and said clutch member having aplurality ofcircumferentially spaced recesses. radially intermediate said zonesandsaid sets of clutch teeth,`,each of said movable elements having: anannular part carrying. the friction surfacefthereof and a plurality ofcircumferentially spaced parts respectively extending into saidrecesses, those parts in each recess being -arranged in axialoverlapping relationship and the overlapping part of oneof each of saidelements being engageable with the otherof said elements to limitmovement of said elementsone toward the other, and spring means actingon at least oneof the first mentioned friction parts to lbiasthe sameinto continuous frictional engagement with its-'said cooperatingfriction clutch element. 4.. A power transmitting mechanism comprising'in combination rst and secondrelatively rotatable torque transmittingstructuresa set of clutch. teeth and .a friction clutch part disposedAfor rotation with. each of said structures, a third torque.transmitting structure coaxial with said .first and secondstructures andadapted to be selectively drivingly connected therewith, a clutchrections for selective. clutching. engagement with 'saidsetseofblutchteeth .thereby to provide said selective drive.connections, said clutch member having a plurality of circumferentiallyspaced means including a plurality of relatively circuml ferentiallyspaced projections carried by each of said devices and respectivelycircumferentially registering with the projections of the other device,the said registering projections extending into a common opening in saidclutch member and disposed therein in rotative abutting relationship onewith the other when said clutch member is in its neutral position, theprojections of each device having clearance in the respective clutchmember openings suicient to accommodate limited oscillatory movement ofsuch device and its projections relative to said clutch member, and cammeans carried by the projections of each device cooperable with cammeans of said clutch member when such device and projections are ateither limit of the aforesaid oscillatory movement to form a releasablethrust transmitting connection therebetween for thrust of a ringlikebody into synchronizing engagement with its cooperating friction clutchpart in response to a selected clutching shift of said clutch member.

5. A power transmitting mechanism comprising in combination first andsecond relatively rotatable torque transmitting structures, a set ofclutch teeth and a friction clutch part disposed for rotation with eachof said structures, a third torque transmitting structure coaxial withsaid first and second structures and adapted to be selectively drivinglyconnected therewith, a clutch member rotatably driven With said thirdstructure and adapted to be shifted from a neutral position thereofselectively in opposite axial directions for selective clutchingengagement with said sets of clutch teeth thereby to provide saidselective drive connections, said clutch member having a plurality ofcircumferentially spaced openings therein and cam means adjacent eachopening, relatively rotatable friction clutch devices each including aring-like body axially spaced from the body of the other device andcooperating with an aforesaid friction clutch part to form a frictionclutch, means maintaining the cooperating parts of each such frictionclutch in continuous relatively light frictional engagement prior toselected shift of said clutch member from its neutral position, saidmeans including a plurality of relatively circumferentially spacedprojections carried by each of said devices and respectivelycircumferentially registering with the projections of the other device,the said registering projections extending into a common opening in saidclutch member and disposed therein in radially overlapping rotativeabutting relationship one with the other when said clutch member is inits neutral position, the projections of each device having clearance inthe respective clutch member openings sufficient to accommodate limitedoscillatory movement of such device and its projections relative t0 saidclutch member, and cam means carried by the projections of each devicecooperable with cam means of said clutch member when such device andprojections are at either limit of the aforesaid oscillatory 10 movementto form a releasable thrust transmitting connection therebetween forthrust of a ring-like body into synchronizing engagement with itscooperating friction clutch part in response to a selected clutchingshift of said clutch member.

6. A power transmitting mechanism comprising in combination first andsecond relatively rotatable torque transmitting structures, a set ofclutch teeth and a friction clutch part disposed for rotation with eachof said structures, a third torque transmitting structure coaxial withsaid first and second structures and adapted to be selectively drivinglyconnected therewith, a clutch member rotatably driven with said thirdstructure and adapted to be shifted from a neutral position thereofselectively in opposite axial directions for selective clutchingengagement with said sets of clutch teeth thereby to provide saidselective drive connections, said clutch member having a plurality ofcircumferentially spaced openings therein and cam means adjacent eachopening, relatively rotatable friction clutch devices each including aring-like body axially spaced from the body of the other device andcooperating with an aforesaid friction clutch part to form a frictionclutch, means maintaining the cooperating parts of each such frictionclutch in continuous relatively light frictional engagement prior toselected shift of said clutch member from its neutral position, saidmeans including a plurality of relatively circumferentially spacedprojections carried by each of said devices and respectivelycircumferentially registering with the projections of the other device,the said registering projections extending into a common opening in saidclutch member and disposed therein in rotative abutting relationship onewith the other when said clutch member is in its neutral position, atleast one of the first mentioned friction clutch parts being disposedfor axial movement relative to its torque transmitting structure andsaid means further including a spring acting between Said one frictionclutch part and its said torque transmitting structure biasing said onefriction clutch part axially toward its: cooperating ring-like body, theprojections of each device having clearance in the respective clutchmember openings sufficient to accommodate limited oscillatory movementof such device and its projections relative to said clutch member, andcam means carried by the projections of each device cooperable with cammeans of Said clutch member when such device and projections are ateither limit of the aforesaid oscillatory movement to form a releasablethrust transmitting connection therebetween for thrust of a ring-likebody into synchronizing engagement with its cooperating friction clutchpart in response to `a selected clutching shift of said clutch member.

` '7. A power transmitting mechanism comprising in combination first andsecond relatively rotatable torque transmitting structures, a set ofclutch teeth and a friction clutch part disposed for rotation with eachof said structures, a third torque transmitting structure coaxial withsaid first and secondstructures and adapted to be selectively drivinglyconnected therewith, a clutch member rotatably driven with said thirdstructure and adapted to be shifted from a neutral position thereofselectively in opposite axial directions for selective clutchingengagement with said sets of clutch teeth thereby to providesaidselective drive connections, said clutch member having a plurality ofcircumferentially spaced v,mint inuous relatively light frictionalengagement priorto selected shift kof said clutch member from itsneutral position, said vmeans-including* a plurality` ,ofVrelatiuely.,circumferentially spaced projectionscarriedfby ,each of saiddevices and respectively l-,ircurnf erentially registering with theprojections of theY other device, the said registerin .projections ext.ending into a common open- Vsaid clutch-member and disposed therein ,i

in `rotative Aabutting 'relationship one with the QlQrrWhen saidclutch-member is in its neutral positiomatloast oneof the firstmentioned friction clutch Yparts being disposed for axial movernentrelative-to its. torque transmitting structure andsaid, means further.including a spring acting between; said one frictionclutch part-.andits said torque transmitting,- structure biasing said one; .frictionclutch part axially toward-its coop.- eratingming-like body-saidprojections constitutingf means operating when said-clutch member isrinits neutral position totransmit the aforesaid axial-.spring biasing t0the ring-nrey body o f theother. frictionfcllltolirto `thereby impart athrustto, the latter inan` axial direction l'toengage its cooperatingfriction clutch Vpart,.the-projections of Y,each device having clearancein the respeetivefclutch memberopenings suflicient toaecoinmodater-v=1imited oscillatory-,movement of such evite andrits-projections relative tossici .Clutchmsmbep and; Gammeans Carried bythe projections ,of1 each .ldevice rzooperable lwith cam fmcans'of saidQlutcb'memberrwhsn Such device andprojections arefateither limit of theaforesaid` oscillatory movement to form av releasable thrusttransmitting, connection therebetween for thrustfo/f aring-lile bodyintosynchronizing ensagement vl/,111,112itsv cooperating friction clutchnin response toma-selected clutching shift of se-.id clutch-member. u

.rpo-,power transmitting mechanism comprising comb' ation first andsecondxrelatively rotatabletorqnetransmitting structured-a set ofggzlutclri;13,691,311V a ,l friction `clutch part disposedfon-rotationwith.each ofsaid structures, a third tonquatransmittingstructure coaxial with said first and `second structures and adapted tobe selectively` drivinglyfconnected therewith, a clutch member rotatably:driven with said third structure andadapted to, be shifted from aneutral position thereof seletivelyin opposite axial directions Yfor.Selective clutching engagement withsaid sets of clutch teeth therebyto. provide said selective drive connections, said clutch member havinga plurality,ofgcircumferentially spaced openings thereinand cam meansadjacent each opening, relatively .rotatable `friction-,clutch deviceseach includingsa ring-likebody axially spaced from the bgdyl of theother device andv cooperating with anaforesaid-friction Yclutch partVtoform a friction clutch, means maintaining the cooperating parts ofeachrsuch` friction clutch in continuous relatively light frictionalengagement prior to selected shift .ofsaidclutch member from its neutral,positiomsaid meansrincluding a plurality of relativelyV.circumfcrentially spaced projections carried by each` of said'devicesand respectively clrcumierentially registering With the projectionsOrtheother device, the Said. registering proiestions extending into acommon opening in said clutch member and-disposed thcreinin rotativeabutting: relationship one .withtheother when Saidclutch member is inits neutral position, veach oft-said Vfirst-mentioned clutch parts being,disposed for axial movement relative to its said torque transmittingstructure in a direction one toward the other and toward its cooperatingringliKebOdy, said means further including a spring acting between eachfriction clutch part and its tor-,que transmitting structure biasingsuch part inits said direction, and said projections when in saidabutting relationship maintaining a minimum-axial spacing of saidring-like bodies in oppositionto the biasing action of said spings, theprojections of each device having clearance in the respective clutchvmember openings sufficient -to accommodate limited oscillatory movementof such device and itsv projections relative to: said clutch member,land cam means carried by the projections of-each device cooperable-withcam means of said clutch member when such device andprojections are ateither limit 'of the aforesaid oscillatory movement to form a releasablethrust transmitting-connection therebetween for thrust of a ring-likebody into synchronizing enf gagernent with-its cooperating frictionclutch part response to a selected Vclutching shift of saidclutch-member. Y.

9j.- -zIn a power transmitting mechanism, in combination, axially spacedtorque transmitting driving.: .members-,- a set of clutch teethrotatably druiven withv each ci said members, a torque transmittingstructure adapted to be selectively driven fromsaid members including apositive clutch memberfaxially oppositelyshiftable to selectively clutchwith the teeth of said sets tc provide said selective driveconnections,a friction clutch respectively:controlling clutching of said clutchmember Ywith saidsets of clutch teeth including axially-spaced firstfrictionclutchxelements respectively-:rotatably driven with said membersand second friction clutchelements respectively associated with thefirst velementsl and rotatably drivenu with said third structure"for'limitcd oscillatory movement relative thereto` and relative toe'achother, the second element-oi eachV frictiongiclutchbeing adaptedfonmovement to its aforesaidl limit by relatively light frictionalengagement with its.V associatedrst element and eaehsecondzclement whenatsuch limit having means cooperable with the positive clutch membei` to,releasably bleek a selected clutching shift thereon., al spring actingbetween each 'torque transmitting member and the firstfrict-ion clutchelementrotatable therewith continuously biasing the-last element intorelatively light frictional engag-ement with its associated` secondfriction clutch element, said second friction clutch elements reactingone against the other in opposition to the biasing of said springs. f fl f I 10. In a power transmitting mechanism, in combination, axiallyspaced, torque transmitting driving members, a setA of clutch teethrotatably driven with each of said members, a torque transmittingstructure adapted to be selectively driven from Asaid members includinga positive clutch member axially oppositely shiitable to selectivelyclutch with the 'teeth of said sets to provide said selectivedriveconnections, a friction clutch respectively controlling clutching ofsaid clutch member'with said sets of clutch teeth includingv axiallyspaced rst friction clutch elements respectively rotatably driven withsaid members and Second friction clutch4 elements respectivelyassociated with the first elements and rotatably driven with said thirdstructure for limited oscillatory movement relative thereto and relativeto each other, the second element of each friction clutch being adaptedfor movement to its aforesaid limit by relatively light frictionalengagement with its associated first element and each second elementwhen at such limit having means cooperable with the positive clutchmember to releasably block a selected clutching shift thereof, a springacting between each torque transmitting member and the first frictionclutch element rotatable therewith continuously biasing the last elementinto relatively light frictional engagement with its associated secondfriction clutch element, said second friction clutch elements reactingone against the other in opposition to the biasing of said springs, atleast one of said torque transmitting members and the rst frictionclutch element having adjacent faces, said one member having a recesscommunicating with its said face and the biasing spring extending intosaid recess and engaging the said face of the last mentioned firstfriction clutch element.

11. In a power transmitting mechanism, in combination, axially spacedtorque transmitting driving members, a set of clutch teeth rotatablydriven with each of said members, a torque transmitting structureadapted to be selectively driven from said members including a positiveclutch member axially oppositely shiftable to selectively clutch withthe teeth of said sets to provide said selective drive connections, afriction clutch respectively controlling clutching of Vsaid clutchmember with said sets of clutch teeth including axially spaced firstfriction clutch elements respectively rotatably driven with said membersand second friction clutch elements respectively associated with thefirst elements and rotatably driven with said third structure forlimited oscillatory movement relative thereto and relative to eachother, a second element of at least one of the friction clutches beingmounted for axial movement relative to the torque transmitting memberwith which it is rotatably driven, and means maintaining the elements ofeach friction clutch in relatively light frictional engagement prior toa selected shift of said positive clutch member including spring meanscontinuously biasing the second element of said one friction clutchaxially into engagement with its associated first element, said secondelements being disposed in rotative abutting relationship when saidclutch member is in its neutral position to limit movement of suchelements one toward the other and to maintain the second element of theother friction clutch in relatively light frictional engagement with itsassociated first element under the influence of the biasing of saidspring means.

12. In a power transmitting mechanism, in combination, axially spacedtorque transmitting driving members, a set of clutch teeth rotatablydriven with each of said members, a torque transmitting structureadapted to be selectively driven from said members including a positiveclutch member axially oppositely shiftable to selectively clutch withthe teeth of said sets to provide said selective drive connections, afriction clutch respectively controlling clutching of said clutch memberwith said sets of clutch teeth including axially spaced first frictionclutch elements respectively rotatably driven with said members andsecond friction clutch elements respectively associated with the firstelements and rotatably driven with said third structure for limitedoscillatory movement relative thereto and relative to each other, asecond element of at least one of the friction clutches being mountedfor axial movement relative to the torque transmitting member with whichit is rotatably driven, and means maintaining the elements of eachfriction clutch in relatively light frictional engagement prior to aselected shift of said positive clutch member including spring meanscontinuously biasing the second element of said one friction clutchaxially into engagement with its associated first element, said secondelements being disposed in rotative abutting relationship when saidclutch member is in its neutral position to limit movement of suchelements one toward the other and to maintain the second element of theother fric tion clutch in relatively light frictional engagement withits associated first element under the influence of the biasing of saidspring means, the last mentioned torque transmitting member and the saidsecond friction clutch element rotatably driven therewith havingadjacent faces and such member having a recess therein communicatingwith its said face, said spring biasing means including a springextending into said recess and engaging the said face of said secondfriction clutch element.

13. A power transmitting mechanism comprising in combination first andsecond relatively rotatable torque transmitting structures, a set ofclutch teeth and a friction clutch part disposed for rotation with eachof said structures, a third torque transmitting structure coaxial withsaid rst and second structures and adapted to be selectively drivinglyconnected therewith, a clutch member rotatably driven with said thirdstructure and adapted to be shifted from a neutral position thereofselectively in opposite axial directions for selective clutchingengagement with said sets of clutch teeth thereby to provide saidselective drive connections, relatively rotatable friction clutchdevices respectively associated with said friction clutch parts to formfriction clutches, each device including a body, spaced axially from thebody of the other device, having a friction clutching surface andadapted for thrust movement in an axial direction away from the otherbody to effect relatively heavy, frictional synchronizing engagement ofthe clutching surface thereof with its associated friction clutch part,a projection carried by each body .having a lost motion connection withrespect to said third structure accommodating limited oscillatorymovement of such projection and its body relative to said thirdstructure and said clutch member in response to relatively lightfrictional engagement of such body with its associated friction clutchpart, said clutch member and each device having means cooperable to forma thrust transmitting connection therebetween when the projection andbody of such device are at a limit of the aforesaid oscillatory movementto thereby thrust the body of such device in its said axial direction ofmovement in response to a selected shift of said clutch member, thefriction clutch part of one of said friction clutches being mounted foraxial movement, and spring means continuously biasing said one frictionclutch part axially toward its associated friction clutch device body,the projection of each device rotatvely engaging the other device whensaid clutch member is in its neutral position to limit movement of saidbodies one toward the other and to posi-l tion the friction clutchdevice body of said one friction clutch in continuous relatively lightfrictional engagement with its spring biased friction clutch'p'artsprior to shift of'said clutch member frornits neutral position, saidprojections when so engaged operating to transmit the biasing ofsaid'spring means to the friction clutch device body of the otherfriction clutch and through the' transmission of such biasing and saidlimiting movement maintaining the last mentioned body incontinuousrelatively light frictional engagement with its associated frictionclutch part prior to shift of said sleeve from its neutral position.

14. A power transmitting mechanism comprising in combination first andsecond relatively rotatable torque transmitting structures, a 4set ofclutch teeth and a friction clutch part dispfOSed for rotation witheachof said structures, a third torque transmitting structure coaxial withsaid first and second structures and adapted to be selectively drivinglyconnected therewith, a clutch member rotatably driven withsaid thirdstructure and adapted to be shifted from a neutral position thereofselectively in opposite axial directions for selective clutchingengagement with said sets of clutch teeth thereby. to provide saidselective drive connections, relastructure adapted to be selectivelydrivingly connected with said rst and second members and coaxialtherewith including an axially stationary rotatable member and a clutchmember rotatably driven with the latter and axially oppositeiy shiftablefrom a neutral position to selectively clutch with said sets of clutchteeth to provide said drives, friction clutch devices respectivelyassociated with said friction clutch parts to provide friction clutches,each device including a friction surface carrying body axially spacedfrom the body of the other device and said bodies being adapted forrelative axial opposite thrust movement for synchronizing engagementwith their respective components, means maintaining the components ofeach friction clutch in continuous relatively light frictionalengagement prior to shiftv of said clutch member from its neutralposition comprising relatively circumferentially spaced projectionscarried by each device engaging the other device when said clutch memberis in its neutral tively rotatable friction clutch devices respcctivelyassociated with said friction clutch parts to form friction clutches,each device-including a body, spacedaxiallyv from the body of the otherdevice, having a friction clutchingsurface and adapted for thrustmovement in an axial* direction away from the other body to effectrelatively 'heavy, frictional synchronizing engage- :mentv oftheclutching surface thereof with its associated friction clutch part, aprojection carried'by'. each body having a lost motion connection withrespect to said third structure accommodating limited oscillatorymovement of such projection and its body relative to said thirdstructure and said clutch member in response to relatively lightfrictional engagement of such body with its associated friction clutchpart, said clutch member and each device havingl means cooperable. toform a thrust transmitting connection therebetween when the projectionand body of such'device are at a limit of the aforesaid oscillatorymovement to thereby thrust the body of such device in its` said axial'-direction of movement inlresponseV to a selected shiftof said clutch.member, Vthefprlojection of eachA device rotatively engaging the otherdevice when said clutch member is in its neutral position to limit axialmovement of said friction clutch device bodies in a direction one towardthe other, each of said friction clutch parts being mounted foraxialmovement, and spring means continuously biasing each of saidfriction clutch parts axially toward the, body of its associatedfriction clutch device and cooperating` with the aforesaid limitingymovement effected by saidprojections to provide said continuousrelatively light i'rictional engagement of the components of eachfriction clutch.,

l15'. In a power transmitting mechanism in combination, first and secondtorque transmitting members, a set of positive clutching teeth rotatablydriven with each member, a friction clutch part associated with Veachmember and including a ring-like body having a friction clutchingsurface at its radially outer periphery andteeth at its radially innerperiphery engaged withl the positive clutch teeth of the associatedmember for rotation therewith and for axial movement relative thereto, atorque transmitting position maintain-ing a predetermined minimum axialspacing of the bodies of said devices, and spring means continuouslybiasing one of said friction clutch parts axially toward the frictionsurface carrying body of the associated device, oneof the.` members ofsaid torque transmitting structure having circumferentially spaced.openings and each projection having a first portion reduced in dimensionrelative to an adjacent portion in a direction generally transverse. tothe longitudinal axis of such projection and extending into anopening-of said one member with clearance therein accommodating limitedoscillatory movement of such projectionsY and the device thereofrelative to the projectionsof the other device and relative to the saidmembers of said torque transmitting structure undertheiniiuence of theaforesaid continuous relatively I ylight frictional engagement, theprojections of eachldevice-having a shoulder at the juncture, of

itsaforcsaid portions thereof disposed in thrust Areceiving,relationship with said. clutch member when such projections are atalimit of oscillatory movement for thrusting. thebody of such device intosynchronizingengagement with its cooperatingclutch part in response to aselected clutching shift of said clutch member.

16. In a power transmitting mechanism in combination, relativelyrotatable first and-second torque transmitting structures, a set ofclutch teeth and a component of a friction clutchro.- tatably drivenwith each of said structures, a third torque transmitting structureadapted to be selectively drivingly connected with said rst and secondstructures and including. an axially stationary rotary member and aclutch member rotatablyconnected therewith axially oppositely shift-ablefrom a neutral position thereof to selectively clutch with theteeth ofsaid sets to pros vide said selective. drive connections, frictionclutch devices respectively associated with said components ,to providefriction clutches respectively, controlling the clutching shifts ci saidclutch member, each device inludingan annular bodyY carrying a frictionclutching surface, adaptedvfor thrust movement into synchronizingengagement with its cooperating component, means maintaining thefriction clutching surface of each of said deviceslvin continuousrelatively light frictional engagement with its associated componentprior to selectedy clutching shift of said clutch member including aprojection extending from the body of each device toward andcircumferentially registering with the projection of the other device,one of the members of said third torque transmitting structure havingan! opening therein and said registering `projections extending intosaid opening with clearance therein accommodating vlimited oscillationof each projection relative to said one member under theiniluence ofsaid relatively light frictional engagement whensaid thirdy structure isrotating asynchronously relative to` said rst and secondstructuresrespectively, each projection having a shoulderinterrnediatedts` length and having a portion overlapping the portion-ofthe other projection and disposed in endwise Irotative abutting4relationship with thefshoulder of such other projection when saidclutch member is in its neutralv position, said clutch member and theprojection of each device having cam means cooperable to'form a'releasable thrust transmitting connection therebetween when suchprojection is at a limit of its oscillatory lmovement operable to thrustthe friction clutching surface of such-device into synchronizingengagement with lits cooperating component in response I to 'a selectedclutching shift of said member.

. .17. In a power transmitting 4mechanism including axially spacedcoaxial torque transmit- ,ting members each having a set of clutch teethand a friction clutch part rotatable therewith, a-torquetransmittingstructure adapted to be selectively drivingly connected with saidmembersl including a clutch member coaxial with said members and axiallyoppositely shiftable from a neutral position to selectively clutch withthe clutch `teeth thereof, friction clutch-elements each having arotatable driven connection with said clutch member respectivelycooperating with said parts to form friction clutches, said elementsbeing adapted for relative axially opposite movement one away from theother and each having means cooperable-with said clutch member to form athrust transmitting connection therebetween for moving such element asafore said into `synchroniaingl engagement with its cooperating frictionpart in response to a selected shift of said clutch members and saidelements being movable one towardthe'o'ther one of said term-,1etransmitting members; having van opening therein, and a spring extendinginto-said opening biasing thecsaid friction l.clutch part rotatable withsaid one member into engagement-with its said cooperating frictionclutch element to release saidsyn'chronizing engagement-said clutchmember f -having an opening therein and each of said movable elementshavingla part thereofextendinginto saidv opening to` form said rotatabledrive connection and rotatively engaging the other element prior toshift of said clutch member from its neutral position to limit the lastmentioned movement of said movable elements. Y

18. In a power transmitting mechanism including axially spaced coaxialtorque transmitting driving members each having a set of clutch teethand a friction clutch part rotatable therewith, a clutch member coaxialwith said members and axially oppositely shiftable from a neuu tralposition thereof to selectively clutch with said sets of clutch teeth,friction clutch elements rotatable with said third clutch memberrespectively cooperating with said parts to form friction clutches, saidelements being constructed and arranged for relative axial oppositethrust movement and each thereof having means cooperable with said:clutch member to :form a releasable thrust transmittingA connectionthere.- between for thrustI movement of suchelement into synchronizing`engagement with its cooperating friction clutch 'elementinfresponsetoaselected shift of said clutchmember; the zone of frictionalengagementof each friction clutch being disposed radially outwardly`beyond said sets of clutch teeth and: said clutch member having aplurality of circumferentiallyspaced recesses radially .intermediatesaid zone and said sets of clutch teeth, each of said movable elementshavingl an annular-part` carrying the friction surfacethereof and, ayange extending generally radially inwardly therefrom towardga set ofsaid clutch .teeth and .beyond the radial cuter periphery -of saidclutch member, a plurality of relatively circumferentially spacediingers carried by said ange respectively extending into the recesses ofseid, clutchmember and said flange having openings thereincircumferentially alternatingwithmthe fingers thereof re.- spectivelyAadapted toreceive those portions of said clutch .membercircumferentially. between the recesses-thereof Iwhen said clutch memberis clutchedwith the last mentioned set of clutch teeth, the fingers' of.one of said elements-em gaging the-other element when-said clutch mem+bei' is in4 its neutral; positionzto maintain said annular' parts in. aypredetermined minimum axially spacedzrelationship, .springmeansfcontinucusly lbiasing the frictionv clutch part. of one of saidfriction clutches. into engagementwith its associated friction clutch.-element and the fingers of i said friction` clutch elements lwhenengaged asaforesaid `operating to transmit the biasing of i said springmeans to thev friction clutch element of theother friction clutchthere-- by biasing the last mentioned element into engagementwith itsassociated friction clutch part.

19. A power transmittinglmechanism comprisingin `ccmbinationrst andsecond-relatively rotatable torque-.transmitting structures, aVV set ofclutch teeth-and a frictionclutch Avpart. disposed forrotationzwith eachof said structures, a thirdtorque transmitting'structure .coaxial withsaidnrst and .second structures and adapted to beselectively.ldrivinglyconnected therewith, a clutch memberrotat'ablyfdrii/eny with said third structure and adapted hto befshiftedfrom a neultral position thereof` selectively in opposite-axialdirections i for Vselective clutching engagement with said sets ofclutch 4teeth rthereby to provide said selective drive connections,`relatively ro'n tatable friction-iclutch-devices respectively en'-gageable-Hwith'- saidfriction clutch parts, Aand meansipositioning eachdevicein rotatable frictional driving-,engagement with its associatedfrictional clutch part prior to selected shift of saidA clutch-'memberfrom its neutral position comprisingl axially `extending `projectionsrespectively carried by said devices for rotation there'- 4with andagainst circumferential and axial move'- ments relative thereto, theprojection carried by each device having a lost-motion rotary connectionrelative to said clutch member accommodating limited rotation of suchprojection and its device relative to said clutch member in response tofrictional driving engagement of such device with its associatedfriction clutch part and rotatively axially abutting the other devicewhen said clutch member is in its neutral position, and blocker meanscarried by each projection disposed in position to releasably block 'aselected clutching shift of said clutch member 19 when such projectionis at a limit of its aforesaid rotary movement.

20. A power transmitting mechanism vcomprising in combination rst andsecond relatively rotatable torque transmitting structures, a set ofclutch teeth and a friction clutch part disposed for rotation with eachof said structures, a third torque transmitting structure coaxial withsaid first and second structures and adapted to be selectively drivinglyconnected therewith, a clutch member rotatably driven with said thirdstruc'- ture and adapted to be shifted from a neutral position thereofselectively in opposite axial directions for selective clutchingengagement with said sets of clutch teeth thereby to provide sai-1--selective drive,` connections, relatively rotatable friction clutchdevices respectively engageabs with said friction clutch parts, andmeans posi tioning each device in rotatable frictional driv ingengagement with its associated frictional clutch part prior to selectedshift of said clutch member fromi its neutral position comprisingaxially extending projections respectively carried by saiddevices forrotation therewith and against circumferential "and axial movementsrelative thereto, the projection carried by each deviez having alost-motion rotary connection relative to said clutch memberaccommodating limited rotation of such projection and its devicerelative to said clutch member in response to frictionai drivingengagement of such device with its asso-- ciated friction'clutch partand rotatively axially abutting the other device when said clutch memberis in its neutral position, and blocker mean:- carried by eachprojection disposed in position toreleasably block a selected clutchingshift of said clutch member when such projection is at a limit ofv 'itsaforesaid rotary movement-said positioning means further includingspring means said parts being axially spaced and one thereof v beingdisposed' for movement relative to lits said structure, a'clutch memberbetween said sets of clutch teeth yand oppositely axially shiftable toselectivelyfclutch therewith, friction clutch elements respectivelyyassociated with said vfriction clutch parts; each element includingVblocker means movable between a position to allow a selected clutchingshift of said member and a posie tion to releasably block the same inresponse to frictional driving engagement between such element and itsassociated clutch part, and means maintaining each associated elementand part insaid f rictional driving engagement prior to selectedclutching shift of said member from its neutral position comprising agenerally axially extending projection supported at one end thereof byone of said friction clutch elements for rotation therewith androtatively abutting the other of said friction clutch elements when theclutch member is in its said neutral position and limiting movement ofsaid elements one toward the other, said means further including springmeans biasing said one friction clutch part into frictional'engagementwith its associated friction clutch part. 22. In a power transmittingmechanism, first and second rotatable torque transmitting structureseach having a set of clutch teeth and a friction clutch element disposedfor rotation therewith, a third rotatable torque transmitting structurecoaxial with and adapted to be selectively drivingly connected with saidfirst and second structures, a clutch member rotatably driven with saidthird structure and adapted to be shifted from a neutralV positionthereof for selective clutching' engagement with said sets of clutchteeth thereby to provide said selective drive connections, said memberhaving a plurality of cire cumferentially spaced openings therein,relativef ly rotatable friction clutch devices respectively associatedwith said friction clutch elements and having a body part provided witha friction surface engageable with the associated friction clutchelement and spaced axially from the body part of the other device, eachdevice including a part circumferentially and axially rigid with thebody part thereof and projecting axially therefrom into an opening insaid clutch member with circumferential clearance therein, theprojecting part of each device having blocker means adapted to bedisposed in position to releasably block a selected clutching shift ofsaid clutch member in response to frictional driving engagement of theclutching surface of'such device with the associated friction clutchelement, the projecting part j of each device rotatively axiallyabutting the other device to position the friction clutching surface ofeach device in continuous frictional driving engagementwith itsassociated friction clutch element to thereby dispose the blocking meansof each device in the said blockingy position prior to selected vshiftof said clutch member from its neutral. position.

WILLIAM T. DUNN.

REFERENCES CITED The following references are of record in the Y

